Should 15#felt be put under the new layer of shingles (Timberline 30 Home Depot) when reroofing over older asph shingles? I have heard both ways. This is one layer of shingles over ply sheathing being covered by another. AlsoWhats the best way to get rid of any moss between the old shingles
Thanks
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Replies
ex lrrp? wow
the easiest way to get rid of the moss... take the shingles off.
DITTO!
You don't use felt in a shingle-over job. (Of course, many here will choke on the suggestion of a shingle-over anyway.)
There's considerable argument as to whether felt is needed under regular asphalt/organic or asphalt/fiberglass shingles when directly over standard plywood sheathing. It's tradition, but by some accounts pointless.
Just for info:
No felt will get your roof a no-go from my inspector.
He's also a member of our fire department, so he's particular about fire ratings.
Most manufacturers use the felt a part of the "roof system" in order for the roof to achieve the proper burn rating.
Edit: comments are directed towards felt over nekked sheathing...not on a roof-over like this thread is talking about.
Edited 12/19/2004 9:58 pm ET by Mongo
Thanks to you and all else who replied.
I would take off the shingles but I am a 56 yr old man withn a medium bad back so I won't--just getting the new ones on will suffice.
I don't really see the need to pull the old one off anyway, in my location the limit is 3 and this is only the second
Thanks again, all
James
With you having a bad back, I would reccomend you purchase you roofing material from a roofing supply house and have them deliver and load the roof for you. Out here, there is no additional charge for the service. I found that roofing supply house "usually" don't charge any more than what you get at Home Depot, plus, they have a better selection
I got the Guatemalan Forklift to stock it and still paid almost $200 less than Pacific supply would do it and quicker. I disdain HD as a rule but it is right around the corner.
OK guys--I didn't put the felt down in spite of having it on the job (have to grunt it back to HD) I called up the County Building (Contra Costa County, CA) and they said that it was not required and not ordinary if the roof wasn't leaking to start with which it was not. Ony one vapor barrier is required.The shingles were not curling, it was about as sweet a deck for this as you could ask for. Self, son and friend put down 18 squares in one nice sunny California day (Its beginning to look a lot like Christmas, dadedum), them doing the heavy lifting, self mostly doing the pointing and shouting. (I'm a disabled veteran)
Sorry, purists, I know you probably know more about this than me but I have been a carpenter for almost 30 years, a contractor for 24 and I have seen I don't know how many roofs like this laid on top of another that lasted well. Where there was a fault it was in the installation, usually. This is my girlfriends house to sell and I bet they bulldoze it and build a mega house on it anyway, its that kind of setup.
Thanks for all the good advice!
James
Edited 12/22/2004 10:12 am ET by EXLRRP
This thread was worth the trouble to read even if the original poster went ahead and did what he was going to do anyway. These things help provide perspective on time spent on Breaktime. Also, I love it when someone tells the Piffmeister: "your wrong ." I always marvel at those with unshakeable faith and confidence.
I don't do much roofing because, as David Owen said, fighting wars and roofing houses is for young men. But, when I do roofing, I almost always prefer to strip the old shingles for all the usual reasons. There are times when leaving the old shingles makes sense, but I don't often encounter those conditions.
The biggest problem I see is where a roof intersects a wall. Many hacks butt the new roof-over shingles against the wall, and if they're particularly conscientious, they'll squirt some roof cement in the joint. Almost never do they weave the new shingles in with the flashing. I actually saw this procedure recommended in the JLC several years ago because it wasn't competitive to do it properly. Silly me! But I can't help wondering what happens to the water that inevitably gets in that joint.
Al Mollitor, Sharon MA
Al,
I don't know of ANY way to weave the second layer of shingles in with the first layer of step flashing ( and have it look good).--------
however---it is VERY often incredibly simple to simply leave the first layer of shingles and step flashing intact----and install a second layer of shingles and a second layer of step flashing-------particularly if you are working up against vinyl or alyminum siding.
Btw-----despite what Piffen says------dimensional shingles work out VERY well as a second layer installation.
I would say maybe 90% of the roofs we do are complete tear-offs, 2 or 3 layer tear-offs. The remaining 10% are layovers( over 1 layer only).
On the multilayer complete tear-offs we frequently know the age of the house and so we know each layer is AVERAGING over 25 years /layer.That Average would be higher except the top layer is often a dirt cheap 20 year shingle.( 1920's house---3 layers---do the math)
Good luck all, Stephen
Stephen: That was my point about the step flashing. It's not practical to use the old flashing without removing the old shingles. Many "roofers" slap the new shingles on top of the old ones and don't add any flashing at all.
Regarding vinyl siding, I often see the J-channel and siding tight on top of the roofing. I don't know how you could slip new shingles and flashing under there without removing the old roofing, or trimming the siding.
Al
Al,
the problems with the J channel are caused by siding guys who are typically even dimmer than roofers LOL( they have no accountability RE the weather------any leaks caused by the siding will almost surely be blamed on the roof.)
Around here you will often see older aluminum siding with no j channel on the slope. If there IS a J channel in the way it will likely be held in place with only about 5-6 nails over 12 feet-----quite simple to remove it and discard it with no ill effects. vinyl siding is even easier---if needed----to remove the jchannel----trim the vinyl siding in plane and re-install the j channel.
where i DO often run in to a snag is that I like to use a larger step flashing 3x3x8 to keep it compatable with metric sized shingles. typically we will have to trim the vertical face of the step to get it to clear j channel nails----if the j channel is left in place. also---since it can be tight to get the step up under the siding----I will try to get the step in first---then slide the shingle under it--------or if I find a nice loose spot I will put a 10-12 steps up under the siding at once---and then slide 'em up hill or down hill one by one into position.
Stephen
BTW-------my troubles with j channel is MOST likely to be what to do after tearing of 3 layers of shingles---with the gap left between the new single layer of shingles and the siding now stranded about a mile above it!!!!LOL
Edited 12/23/2004 6:59 am ET by Stephen_Haz
Steve, read my comments above to M
curious about your thoughts on using tarpaper for a second roof layer. I never have, but if I had to do an archy shingle over first roof, I would be tempted to insure myself with that ply, especially if it were a lower pitched roof. because the manufactuers ar more stringent about the pitch for archy shingles
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Piffen,
there are very few absolutes in life
BUT----I think one of them would be that I would never,ever,EVER put a layer of felt over a layer of shingles and then try to shingle over the resulting mess.
The REASON is----that doing so would prevent properly nesting the shingles when using the "but up" method of re-roofing----that is butting the top edge of the new shingle up against the lowest edge of the tab portion of a course of shingles on the old roof.
Failing to use the "but-up" method gaurantees ample voids----like those you mentioned wanting to avoid.
Using the " but-up" method----and choosing the proper thickness of new shingle----means that there will be no voids---except over the keyways of the underlying 3 tabs.
Of course doing a layover ---over a dimensional shingle -----would gaurantee plenty of voids---and would best be avoided---------although I have torn off plenty of roofs( very BAD looking roofs indeed) where there were 3 layers
layer #1) a 4 tab shingle---remember seeing those?
layer#2) a old,thick T Lock
layer #3) a fiberglass 3 tab
The last layer of 3 tab often lasted over 20 years----but I will bet it looked horrible the entire 20 years.
BTW---these are steep roofs, and not as succeptible to hail damage (which is pretty rare here)
Before I forget-----when I get the chance I have a thread I want to start that I think you will enjoy( after all of your travel experiences).
Stephen
I always do butt ups on nail overs but most dimensional shingles are metric and most three tabs inplace are english sizing, creating the conflict. if you eliminate voids, you increase odds of poor sealing and wind uplift.
I have torn off a few of those ugly roofs that haad me working all day to get a few squares off
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Most of the nail-overs I have done were in west texas where hail damage usually gives a roof a life span of 6-10 years on average.
We would deal with walls by cutting, chipping, ot teaaring the shuingles away at that point and using plastic roof cememnt spread to glue the shingle to the existing flashing. Most roof penetrations either got new boots or same treatment with getting top of a shingle under the flashing at base end.
In Florida, there would ALWAYS be some rotted sheathing to replace at minimum by time a house was up for re-roof, so tear of was always part of the procedure.
In Colorado and Maine, most of the roofs are curling before owners call for estimates, so there are not too many nail-pvers there either.
The reason I say the dimensional shingles do not fare as well is that any nail over has voids under the shingle. those voids will void the warrantee on any shingle. Dimensional shingles are heavier and hide them better, but they are still there, and too may times I have been called to do repairson dims that were laid over and I find tears and separations in the shingles at those very places, so I have never doen a dimensional layover. When I ignore warrantee requirements, I know that I am buying the risk myself so I am absolutely sure of myself when I do that. Since most nail overs I did were in hail country, you can see how important it is to have solid backing for the shingles.
it is easier for a normal threetab to follow the contour of what lays under it or to adjust the layout to reduce voids than with a dimensional archy type shingle, IMO
BTW, Do you know what I'm wrong about?
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Piffin:
I read your posts with interest and respect. I was referring to Bean and his one-line post.
Al
Al,
personally I am still intrigued by Piffens' apparently talking dog!
Stephen
I am intrigued by the possibility of learning new scientific principles that would allow tarpaper to cause condensation.
BTW, both dog and wife can communicate ideas like that without parting their lips to SAY anything. They can do it with their eyes. Tell me your wife doesn't have any unspoken messages for you from time to time! Now tell me your dog can't tell you it's time to go out - or else.
What I haven't figured out if the dog learned it from the woman or the woman learned from the dog, either way, man does well to listen to what is unsaid by either
;)
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"What I haven't figured out if the dog learned it from the woman or the woman learned from the dog, either way, man does well to listen to what is unsaid by either"Piffen,Neither one of them learned it. They are born with that ability.The question is, which one of them taught you to understand and listen to it.Rich BeckmanAnother day, another tool.
I know on which side my bone is buttered
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I know on which side my bone is buttered
That sounds like nasty talk to me. ;]
Hope you're enjoying your holiday.
I invented the buttered bone.
Piffen,
a metric shingle will layover a standard shingle VERY well------in fact the brand I used most often was advertised at one time as the ideal shingle for layovers.
I like to pay attention to where the glue strip is located on a shingle----this will vary from brand to brand----and also from plant to plant within the same brand.
One brand I use , most often locates the sealdown strip on the UNDERSIDE of the TAB portion of a dimensional shingle----which when laying over a standard shingle will put the sealdown strip in a less than ideal location---the irregular area of different thickness laminations----which will effect maximum sealdown.----------However2 of its colors came from only one plant down south----and those 2 colors had the sealdown strip located on the top surface of the shingle ,up on the flat part of the shingle.
The other brand that I use ALWAYS puts the glue strip in that second location.
One brand( or color---plant selection----) of the same brand will work out better in some situations than in other situations.
So---we are often juggling a combination of competing factors to accomplish the best total outcome to meet the customers needs----balancing the potential drawbacks of one material or technique with its potential benefits. Ironically---if I was to insist on adhering to a specific unwavering rule---I might be forced to deliver a product less suited to the needed task.
I am QUITE sure you do the same---that's the advantage of experience isn't it? The ability to use your experience to determine what overall will be BEST for THIS situation------and the wisdom to know that the same material or technique might not be BEST for the neighbor next door.
Best wishes, Stephen.
I agree totally with your last paragraph, which is why I suggested to the original poster here, that he would be better served to strip the roof.
But as to experience and judgement affecting decisions like this - I often find that some weekender or hack will do as they have seen me do on something and say that it must be right because piffin does it this way, without the knowledge of why I did something and that tcircumstances in the case of their job are half way around the world different than in the case they had observed, yet claiming my imprimatuer on their process. That is why we so often recommend hiring an experienced, reputable person such as yourself to do a job.
A more humorous example of the sane concept is the young guy who went out and bought the same brand of roofing hatchet that I was using on the assumoption that it contained some sort of magic to explain why I was laying twice as many shingles in a day as he was.
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Well Piffen,
I hope you were kind enough to explain to the young buck that speed in hand nailing doesn't come so much from the hatchet hand----as it does from the nail hand.
( of course the hatchet may determine how LONG you can hand nail----but not so much how fast)
RE: experience and judgement
virtually everybody I ever hired got the same little talk---" If you see me doing something and you feel you have a better way---- Let me know----I would be happy to learn a better way"
What I learned in the end was that talk was ALMOST always a mistake. Over the years----worker after worker would say" Hey , I have a better way--- we always do it THIS way........" and they would proceed to show me techniques I had discarded years before.Almost always ----the new worker had a technique that worked OK----but they had not yet experienced the situation where their technique was a catestrophically BAD idea.----And ---so when you tell them " sorry---that isn't a better way"---then you have an argument on your hands.
This problem is most prevalent with guys who start out doing new construction---and then are crossing over to work on old houses. In new construction the premium was on speed, combined with the fact that they might switch employers every few months------they never saw the results of their poor judgement---which might not result in a call back untill they were YEARS down the road.
and then of course there is the OLDER employee who insists he has a better way------and for HIM it will be better---'cause its easier---and the liability is on MY shoulders.
this is how we get reputations for being "curmudgeons"-----the burden of HAVING to always be right---or risk getting sued
Stephen
isn't it amazing how a little leak can eat up all the profits of a roofing job ?
just one little leak from one guy and one piece of flashing... or one nail in the wrong place ..
Mike Smith Rhode Island : Design / Build / Repair / Restore
Mike,
EXACTLY!!!!!!
one little leak caused by one guy with his head up his AZZ, po'ed by something his wife said last night, or upset about his pay rate, or wondering if he can get time off to go to some metal head concert---or any of a zillion possible things.
As many of us know----it's a whole 'nother ball game when it's your own name on the door.
Stephen
me? Curmudgeon?
No arguments here - my way is the only way other than the highway
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I knew that. I just thought you might have some insight for me and asked tongue in cheek
Welcome to the Taunton University of Knowledge FHB Campus at Breaktime. where ... Excellence is its own reward!
Don't shingle over if the existing shingles are curled -- the curl will show through in short order and the roof will look like crap. Shingling over is OK (though not "good") if the existing shingles are just worn and cracked. Note that any really bad shingles (missing tabs, etc) should be replaced before covering them, to maintain a reasonably nice appearance for the top layer.
Question one....
no.
Question two....
toothbrush.
Next?
J. D. Reynolds
Home Improvements
"DO IT RIGHT, DO IT ONCE"
No . Don't use the felt you will just be making for more water to be traped. Through condensation . The area can't dry out because the felt will trap the water . You think you have moss now .
Not true.
If everthing is installed properly and adequate ventilation is provided below the roofs surface,(attic) there will be no condensation.
Do it right the first time
Hube
The guy is talking about going over an existing roof . Installing felt first will cause condensation . Do it right . Strip the roof
if threere is water present and he papers over it, the moisture will be trapped temporarily, but there is no way in hades that tarpaper will 'cause' condensation, in any circumstances.
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Your wrong .
My wife and dog have both been known to say the same thing, but either one can give a better reason for their opinion than you can
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Piffen,
I can understand your WIFE telling you that you are wrong------------but it is simply un-acceptable to take that sort of thing from your dog.
On the other hand-------most likely those voices in your head come from WITHIN----and you really shouldn't blame 'em on the dog. LOL
Best seasonal wishes to you Piffen, what ever holidays you choose to celebrate.
Stephen
Wow, I saw the email and thought you had already replied to my comments before I posted them.
Thanks and same to you. I'm visiting stepson in north Idaho for the week. can't ever get much done around chrismass week anyhow and this makes the wife and dog happy so I can be right again
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I was waiting to see other responses . Stephen Haz has it right . Why would someone compare there wife with there dog ? Go figure.
Both my close companions, from top of the intelligence level to the bottom of intelligence level, covers pretty well all the span in between, and both exhibit more intelligence in their responces than what yours did.you wanna start fresh?
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O.k.
All i'm saying is in my opinion going over an existing roof , with another layer of felt , then another roof . Is an area where temerature change can occur . This then can form condensation . There is no danger to the roof . However if ther is a good penetration in the first roof exposed to the wood , this is the area where breakdown and rot will occur. Sorry for the lack of communication on my part .
We both agree that stripping to the wood is the best way to attack this job.If moisture is present, the tarpaper can trap it and results can APPEAR as condensation. But for any condensation to occour, there must be a source of moisture carried on warm air, meeting up with a cold surface to condense on.If you remove tarpaper, the cold surface is the shingle layer instead, but the condensation would still occour. In either case, if moisture is being carried from inside the building to the roof sheathing, there are far greater problems to be dealt with. The presence of the warm moist air is what causes the condensation
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I have a bad back too, so I hire heavy stuff like this out. one reaason I have that bad back is from over twenty years of roofing experience. I have installed over old shingles many times with normal co,mp shingels, but...
That same experience tells me that putting thirty year archies over old shingles will make sure that thtey klast no more than 20-25 years and that the warrantee will expire the day you put them on. get help stripping the old roof off. Archy type shingles are more sensitive to incongruities in the substrate.
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Taunton University of Knowledge FHB Campus at Breaktime.
where ...
Excellence is its own reward!
strip the old roof off first, you'll be glad you did later
the new shingles will last longer and look better
caulking is not a piece of trim